Cleaning of sealing surfaces of doors and door frames of horizontal coke ovens



Oct. 2, 1962 G. E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS l4 Sheets-Sheet 1 Filed Dec. 16, 1958 Oct. 2, 1962 G. E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS Filed Dec. 16, 1958 14 Sheets-Sheet 2 Oct. 2, 1962 G E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR 1958 FRAMES OF HORIZONTAL coma: OVENS 16,

14 Sheets-Sheet :5

Filed Dec.

53st. 2, 1962 G. E. c. RANDELL ETAL 3,055,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS Filed Dec. 16, 1958 14 Sheets-Sheet 4 Oct. 2, 1962 Gv E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS l4 Sheets-Sheet 5 Filed Dec. 16, 1958 Iii- Oct. 2, 1962 G. E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS l4 Sheets-Sheet 6 Filed Dec. 16, 1958 1962 G E. c. RANDELL ETAL ,05

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS Filed Dec. 16, 1958 14 Sheets-Sheet 7 G. E. c. RANDELL ETAL 3,056,699 NG OF SEALING SURFACES OF DOORS AND DOOR Oct. 2, 1962 CLEANI FRAMES OF HORIZONTAL COKE OVENS 14 Sheets-Sheet 8 Filed Dec. 16, 1958 Oct. 2, 1962 G. E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS l4 Sheets-Sheet 9 Filed Dec. 16, 1958 Oct. 2, 1962 e. E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS l4 Sheets-Sheet 10 Filed Dec. 16, 1958 Oct 1 2 G E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS Filed Dec. 16, 1958 14 Sheets-Sheet 11 Oct. 2, 1962 G. E. c. RANDELL ETAL 3,056,699

CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL coma OVENS Filed Dec. 16, 1958 14 Sheets-Sheet l2 14 Sheets-Sheet l3 RANDELL ETAL Oct. 2, 1962 G CLEANING OF SEALING SURFACES OF DOORS AND DOOR FRAMES OF HORIZONTAL COKE OVENS Filed Dec. 16, 1958 E my M c. RANDELL ETAL 3,056,699

F DOORS AND DOOR l4 Sheets-Sheet 14 G. CLEANING OF SEALING SURFACES O FRAMES OF HORIZONTAL COKE OVENS Oct. 2, 1962 Filed Dec.

iiited States This invention concerns a new or improved method of and apparatus for cleaning the sealing surfaces of the doors and door frames of horizontal coke ovens, especially where the doors are of the so-called selfsealing type.

Self-sealing doors for coke ovens have a sealing strip extending therearound and presenting a knife edge to the door frame for sealing therewith. Desirably the sealing strip is resiliently mounted on the door and frequently is furnished along one edge of, or forms part of, a carrier member of angular, approximately U-shaped, or Z-shaped cross-section secured to the door, such sealing strip and carrier member comprising parallel vertical or side portions and horizontal top and bottom portions connected by corner portions to the said vertical or side portions.

It is well known that the eflectiveness of the seal made between a self-sealing coke oven door and its frame depends upon the sealing surfaces located between them being initially clean and that, because of the formation of deposits (which are largely of a pitchy nature) on the sealing surfaces, it is necessary periodically to clean these surfaces. This cleaning is at present performed manually and is tedious and arduous work and work which is not easy efiiciently to perform because of the prevailing heat conditions in the vicinity of a coke oven door frame.

Various proposals have been made in the past for mechanically effecting the cleaning of the sealing surfaces of coke oven doors and frames for such doors but, as far as we are aware, these proposals have not met with success and have not been generally adopted in the coke oven industry.

An object of this invention is, therefore, to provide a new or improved method of and apparatus for mechanically cleaning the sealing surfaces of coke oven doors and frames for such doors.

We have found that when a coke oven door is removed from its oven end, the pitchy substances that have been deposited upon the sealing surfaces of the door and door frame quickly solidify. Moreover, the deposits on the sealing surfaces of the door itself solidify more quickly than those on the door frame at the end of the oven, and this is particularly true in the case of selfsealing doors where the door sealing surfaces are in the form of resiliently mounted metal sealing strips as above explained, these sealing strips losing the greater part f their heat quite rapidly once the door is removed from its frame and away from the oven.

As a result of considerable research we have discovered that the cleaning of the sealing surfaces of coke oven doors and door frames can be effected mechanically considerably more efficiently than hitherto by applying heat to the surfaces to be cleaned immediately before and/or simultaneously with the exertion of a mechanical scraping action thereon.

Thus according to one aspect of this invention there is provided a method of cleaning the sealing surfaces of the doors of horizontal coke ovens and/ or the co -operating sealing surfaces of the door frames, such method comprising heating the deposits on the surfaces to be cleaned and immediately thereafter and/or simultaneatent ously therewith removing the softened deposits by mechanically operated scraper means.

According to a further aspect of this invention there is provided apparatus for cleaning the sealing surfaces of the doors of coke ovens and/ or the cooperating sealing surfaces of the door frames, such apparatus comprising mechanically operated scraper means adapted to be traversed over the surfaces to be cleaned, and means for heating the deposits on such surfaces immediately before and/ or simultaneously with the scraping operation.

It is also very desirable to avoid the necessity of subsequently cleaning the said mechanically operated scraper means and, according to a further feature of the invention, these devices are themselves heated so that the material removed from the sealing surface of the oven door and door frame automatically wholly or largely fall from the said scraper means, leaving the latter substantially clean,

The requisite heat may be applied directly to the surfaces to be cleaned and/or indirectly thereto by heating the scraper blades. Even if heat is applied directly to the surfaces to be cleaned it is also desirable to apply heat to the scraper blades since this aids or reduces as above explained, the necessity for cleaning the scrapers themselves after a sealing surface cleaning operation.

It should be understood that in referring to the application of heat to the surfaces to be cleaned, it is intended to convey that heat extraneous or supplementary to that initially possessed by the surfaces to be cleaned is applied to the latter.

The application of the extraneous heat may be effected by flames directed on to the deposits on the sealing surfaces or on to the scraper blades or by a combination of both these methods. In any case, in order to effect the self-cleaning of the scrapers themselves, these should preferably be maintained at a temperature sufficiently high to ensure that the pitchy deposits removed from the sealing surfaces will not continue to adhere to the scrapers but will be deposited by the latter as they perform their scraping operations.

The heating may conveniently be achieved by means of aerated gas flames and the gas used may be coal gas, propane, butane, or any other appropriate gas.

Although it is preferred to use a gas flame for applying the required extraneous heat, other means may be employed for thi purpose. For example jets of hot gases could be used or the scrapers may be electrically heated and/ or electrical heat radiating devices may be provided and arranged to travel with or precede the scraper blades, such electric heating means being used either separately or in conjunction with gas flames and/or jets of hot gases.

The invention also resides in the mechanical sealing surface cleaning apparatus itself: thus according to a further aspect of the invention there is provided apparatus for mechanically cleaning the sealing surfaces of the doors of horizontal coke ovens and/or the frames for receiving such doors, such apparatus comprising scraper means for scraping the horizontal and vertical or side portions of the said sealing surfaces, a supporting structure carrying said scraper means and adapted for arrangement adjacent to the sealing surfaces to be cleaned thereby to position said scraper means with respect to said sealing surfaces, and means for mechanically propelling such scraper means over the sealing surfaces to be cleaned thereby in such manner that the scraping is always performed in a direction having no upward component.

According to a further aspect of the invention there is provided apparatus for mechanically cleaning the sealing surfaces of the doors of horizontal coke ovens and/ or the frames for receiving such doors, such apparatus comprising scrapers respectively for cleaning the horizontal top, the horizontal bottom and the vertical or side portions of said sealing surfaces, a supporting structure on which said scrapers are mounted and adapted for arrangement adjacent to the said sealing surfaces thereby to position the scrapers with respect to the latter, means for traversing the said scrapers relatively to the said supporting structure and over the said sealing surfaces in such manner that their scraping actions are always exercised in a direction not opposed to that in which gravity acts on the deposits being removed from the sealing surfaces by the scrapers.

According to another aspect of the invention there is provided apparatus for mechanically cleaning the sealing surfaces of self-sealing doors for horizontal coke ovens and of the door frames for receiving such doors, such apparatus comprising a supporting structure adapted for arrangement adjacent to the sealing surfaces to be cleaned, a plurality of scrapers carried by the said supporting structure and movable relatively thereto for cleaning the said sealing surfaces, and means for mechanically moving said scrapers over the surfaces to be cleaned including turning selected scrapers around the corner portions of the said sealing surfaces located between the vertical or side and top and bottom portions respectively of such surfaces, thereby to clean said corner portions.

In accordance with a further aspect of the invention there is provided apparatus for mechanically cleaning the sealing surfaces of a self-sealing door for a horizontal coke oven and of the frame for receiving such door, such apparatus comprising a supporting structure, at least two horizontally reciprocable scrapers carried by said structure, means for reciprocating said scrapers relatively to such structure so that each scraper cleans at least a part of a horizontal portion of said sealing surfaces and for causing such scrapers respectively to sweep, at opposite ends of the travel of the scrapers, around one corner of the said sealing surfaces at a junction between the horizontal and vertical portions of the latter.

According to yet another aspect of the invention there is provided apparatus for mechanically cleaning the sealing surfaces of self-sealing doors for horizontal coke ovens and of the door frames for receiving such doors, such apparatus comprising scrapers for respectively cleaning the horizontal top, the horizontal bottom and the vertical or side portions of the said sealing surfaces, a supporting structure adapted for location adjacent the sealing surfaces to be cleaned and on which structure the said scrapers are all mounted for traversal over their respective top, bottom and vertical or side portions of said sealing surfaces, means for traversing said scrapers over said sealing surfaces and for turning selected scrapers around the corner portions of the said sealing surfaces which lie between the said horizontal and vertical or side portions thereof.

Desirably the scrapers for cleaning the horizontal top, the horizontal bottom and the vertical or side portions of the said sealing surfaces are mounted on individual carriages individually reciprocable on said supporting structure respectively in horizontal and vertical directions, power means being provided for effecting such reciprocation.

In a preferred arrangement each horizontally reciprocable carriage has a pair of laterally spaced horizontal scraper shafts arranged at right angles to the path of travel of their carriage, each of said shafts being provided at its forward part with a scraper blade, and means being provided whereby, at each end of each stroke of said carriage, one of said shafts is adapted to lie in the angle of a corner between a horizontal and a vertical portion of said sealing surfaces and whereby that shaft is automatically rotated through an angle of about 90 to cause its scraper blade to sweep around and clean the said corner of the sealing surfaces.

In accordance with a further feature of the invention each horizontally reciprocable carriage is independently traversed by its own power unit which serves also to rotate said scraper shafts, and means are also provided to arrest the carriage at the end of each of its strokes and to prevent rotation of said scraper shafts while the carriage is travelling but which permit them to be rotated by said power unit when the carriage is stationary at the end of any of its strokes.

Conveniently in the case of the carriage bearing the scrapers for cleaning the upper horizontal portion of the said scaling surfaces a friction clutch is provided to prevent rotation of said scraper shafts whilst their carriage is travelling but which permits such shafts to rotate when the carriage is arrested at the end of any of its strokes.

Advantageously in the case of the carriage bearing the scrapers for cleaning the lower horizontal portion of the said sealing surfaces, a friction brake is provided which is adapted to prevent movement of the carriage from either of its end positions until after that scraper shaft which carries the scraper blade for cleaning around the corner at that end of the horizontal portion of the said sealing surfaces at which the carriage is located, has been rotated to effect the cleaning of said corner but which friction brake is adapted then to release the carriage for horizontal travel.

Each of the scrapers for cleaning the said upper horizontal portion of the said sealing surfaces is adapted to scrape such portion in a horizontal direction outwardly from an intermediate position towards a corner portion of such sealing surfaces and then to sweep outwardly and downwardly around such corner, whilst each of the scrapers for cleaning the said lower horizontal portion of the said sealing surfaces is adapted to scrape first downwardly and then inwardly around a corner at one end of such portion and then horizontally inwardly to an intermediate position in such portion.

In an alternative arrangement, instead of the same scrapers being used for cleaning rectilinear portions of the said sealing surfaces and for traversing around and cleaning the corner portions of these surfaces, a separate scraper may be provided for cleaning each corner portion of said sealing surfaces.

According to a further feature of the invention at least two vertically traversable scrapers may be provided for cleaning each of the said vertical or side sealing surfaces, said two scrapers being arranged one above the other and one being adapted to commence downward scraping at the top of the vertical or side sealing surface and the other to commence scraping at an intermediate position down said sealing surface and to continue to the bottom of the latter, such scrapers being presented obliquely to the surface being cleaned and so as to propel the deposits encountered thereby in a downward direction.

Conveniently the said vertically traversable scrapers may be carried by at least one vertically reciprocal side scraper carriage mounted on said supporting structure, means being provided for selectively propelling the said carriage alternately downwardly and upwardly on said supporting structure, for yieldingly holding said scrapers in their scraping positions during their respective scraping operations, and for retracting such scrapers before any upward movement of said carriage occurs.

Desirably the paths scraped by the said side scrapers overlap the paths scraped by the scrapers serving to clean the said corner portions of the sealing surfaces.

Further features of the invention will become apparent from the following description and the appended claims.

In order that this invention may be more readily understood and carried into practice and further features of the same appreciated, certain embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

FIGURE 1 is a vertical section through an apparatus constructed in accordance with this invention for cleaning the sealing and adjoining surfaces (hereinafter referred to as the sealing surfaces) of a self-sealing coke oven door, the figure showing a door supported in a door rack with the sealing surface cleaning apparatus in position to clean the sealing surfaces of the door;

FIGURE 2 is a section on line II-II, FIGURE 1, the door and door rack being omitted from this figure for the sake of clarity;

FIGURE 3 is a section on line IIIIII, FIGURE 1, drawn to a larger scale than FIGURE 1;

FIGURE 4 is a section on line IV-IV, FIGURE 3;

FIGURE 5 is a horizontal sectional plan view of the scraper mechanism for cleaning the top horizontally disposed sealing surfaces of the door and the corners of the latter surfaces at the upper end of the door;

FIGURE 6 is a section on line VI-Vl, FIGURE 5;

FIGURE 7 is a section on line VIIVII, FIGURE 6;

FIGURE 8 is a sectional plan view of the scraper mechanism for cleaning the bottom horizontally disposed sealing surfaces of the door and the corners of the latter surfaces at the lower end of the door;

FIGURE 9 is a section on line IXIX, FIGURE 8;

FIGURE 10 is a section on line X-X, FIGURE 9; FIGURES 11 and 12 are diagrammatic perspective views illustrating the method of operation of the scraper mechanism for the top sealing surfaces of the door and the adjoining arcuate corners of such sealing surfaces;

FIGURES 13 and 14 are diagrammatic perspective views illustrating the method of operation of the scraper mechanism for the bottom sealing surfaces of the door and the adjoining corners of such sealing surfaces;

FIGURE 15 is a diagrammatic view illustrating how, with apparatus illustrated in FIGURES 1 to 14, the deposits removed from the door sealing surfaces are removed from the latter in directions never opposed to, but mainly assisted by, the force of gravity;

FIGURE 16 is a diagrammatic View of the hydraulic circuit of the apparatus shown in FIGURES 1 to 14;

FIGURE 17 is a rear elevation of a scraper blade furnished with electric heating means;

FIGURE 18 is a side elevation of the same;

FIGURE 19 is a sectional plan view of an apparatus for mechanically cleaning the sealing surfaces of a door frame of a coke oven battery;

FIGURE 20 is a section on line XX-XX, FIGURE 19;

FIGURE 21 is an enlarged fragmentary horizontal sectional plan of the scrapers of the apparatus shown in FIGURES 19 and 20;

FIGURE 22 is a section on line XXII-XXII, FIG- URE 21;

FIGURE 23 is a fragmentary side elevation showing the drive for the scraper carriage of the apparatus illustrated in FIGURES 19 to 22.

FIGURE 24 is a part vertical sectional and part fragmentary side elevation of a modified form of apparatus constructed in accordance with this invention for cleaning the sealing surfaces of a self-sealing door for a horizontal coke oven;

FIGURE 25 is a section on line XXV-XXV, FIG- URE 24, drawn to an enlarged scale;

FIGURE 26 is a front elevation, drawn to the same scale as FIGURE 25, of the upper part of the apparatus shown in FIGURE 24 showing in particular the means for scraping the upper horizontal portions and radiused corners of the sealing surfaces of the door;

FIGURE 27 is a section on line XXVII-XXVII, FIGURE 25;

FIGURE 28 is a section on line XXVIIIXXVIII, FIGURE 26;

FIGURE 29 is a section on line XXIXXXIX, FIG- URE 28;

FIGURE 30 is a section on line XXX-XXX, FIG- URE 26; and

FIGURE 31 is a section on line XXXI-XXXI, FIG- URE 30.

The oven door sealing surface cleaning apparatus hereinafter described with reference to FIGURES 1 to 16 is designed first to clean the upper horizontal and corner sealing surfaces of the door from approximately the centre of the upper horizontal surface outwardly, then to clean the side or vertical sealing surfaces in a downward direction and finally to clean the lower corner and horizontal sealing surfaces commencing at. the corners and working inwardly.

The apparatus shown in FIGURES 19 to 24 inclusive is intended for cleaning the sealing surfaces of the door frame at the end of a coke oven and into which a selfsealing door is intended to fit, whilst the arrangement described with reference to FIGURES 24 to 31 for cleaning the sealing surfaces of a self-sealing door differs in some respects from that shown in FIGURES 1 to 16; nevertheless in each case means are preferably provided for applying extraneous or supplementary heat to the surfaces to be heated and to the scrapers themselves.

Referring to FIGURE 1 of the drawings it will be seen that apparatus of the invention is there shown in use in conjunction with a door holding rack I such as is provided at the present time in horizontal coke oven batteries, usually at one end of the battery, the door being carried by a door handling machine to the end of the battery and mounted in this rack for subsequent cleaning.

The door sealing surface cleaning apparatus according to this invention may, however, alternatively be mounted upon a door extracting machine or on a coke guide machine or pusher machine including a door extracting mechanism as described in our application Serial No. 780,799, executed of even date, now Patent 2,986,758.

As will be seen from FIGURE 1, a coke oven door 2 is supported in the rack 1 by engaging the usual lip 3 of the door upon a transverse member 4 of the rack, the door being secured to the rack by engaging the latch bars 6 of the door with latch hooks 5 on the rack.

The door sealing surface cleaning apparatus is, in the embodiment being described, included in a machine 7 movable to and from the rack; 1 in a direction at right angles to the vertical plane containing this rack, the machine comprising a carriage 8 mounted on rails 9 projecting perpendicularly from the rack 1 and suitably supported on cross bearers It At the front thereof the carriage 8 supports, in a vertical plane, an oblong frame 11 (see FIGURES 1 and 2 in particular). Upon this oblong frame are fixed at vertically spaced intervals four horizontally disposed door-locating yokes 12, the front end portions 13 (see FIGURE 3) of whose arms are cranked inwardly to receive the door 2 between them and centralise it in the frame II. The yokes 12 are additionally supported by vertical members 14 and 15 forming part of the framework of the machine 7 and mounted on the carriage 8. Conveniently the frame 11 and the other parts of the framework of the machine 7 is fabricated from profiled section metal and is furnished with appropriate reinforcing members and struts which need not be described in detail.

The machine 7 is adjustable as a whole along its rails 9 by a double acting hydraulic ram and cylinder assembly 16 of which the ram is secured to an outrigger 17 of the machine framework Whilst the cylinder is connected to any suitable rigid structure 18 (FIGURE 1) relative to which the machine 7 may move, hydraulic pressure fluid being supplied from a suitable source under the control of an operator to advance or retract the carriage 8 towards or away from the door rack 1 as will hereinafter he described. It will, of course, be clear that alternative mechanism may he used for advancing and retracting the carriage 8 with respect to the rack 1 as, for example, a screw and nut arrangement. It will also be appreciated that it would be possible to have the machine 7 stationary a and to arrange for the rack 1. to be moved towards or away from the machine or for both the machine and the rack to be mutually adjusted towards or away from one another.

In the oven door 2 illustrated in the drawings the sealing strip 19 (see FIGURES 3, 4, 5 and 15, for example) is of angular cross-section and is rigidly carried by a slightly resilient carrier member 21! of U-shaped crosssection so that the sealing strip 19 is capable of a slight degree of yielding when applied to the frame of the end of a coke oven designed to receive the door. The sealing strip 19 and carrier member 20 are together in the form of an elongated oblong frame as is very clearly seen in FIGURE 15, comprising vertical parallel side portions 21 and top and bottom horizontal portions 22 and 23, the latter being united with the side portions by corner portions 24, 25, 26 and 27 hereinafter generally referred to as corners or arcuate corners.

The mechanism for cleaning the top horizontal and corner sealing surfaces 22, 24 and in the manner above referred to is shown in FIGURES 5, 6 and 7 of the drawings and comprises a pair of similar scraper blades 28 and 29 having their forward edges contoured as seen in FIGURE 5 and respectively fixed replaceably upon the front ends of horizontally arranged scraper shafts marked 30* and 31 respectively.

The scraper blades 28 and 29 extend radially from the front ends of their shafts 3t and 31 and these shafts are journalled respectively in bearings 32 and 33 depending from the underside of a top scraper carriage 34', reciprocable on a pair of parallel horizontally disposed rails 35 suspended from a superstructure 36 at the top of the framework of the machine 7 and arranged immediately behind the oblong frame 11.

The shafts 30 and 31 are arranged with their axes in the same horizontal plane but are spaced apart along the carriage 34 which comprises a substantially rectangular plate 37 furnished with a pair of longitudinally extending parallel upstanding Webs 38 located between the guide rails 35 and carrying at each end thereof a pair of superposed rollers 39 rotatable 0n horizontal axes and between the rollers of each pair of which inwardly directed flanges of the rails 35 are received. Movement of the carriage 34 transversely of the rails 10 is avoided by the provision on the carriage of rollers 4t) which bear on the inner edges of the inwardly extending flanges of the rail 35.

The shafts 3t} and 31 are capable of a limited degree of sliding axial movement in their journals 32, 33 and are urged forwardly to press the scrapers 28 and 29 into engagement with the sealing surfaces to be scraped, by means of helical springs 41 and 42 respectively arranged around the said shafts and engaging, at their front ends, against collars 43 and 44 fixed upon the shafts and, at their rear ends, against sleeves 45 and 46 respectively keyed to the shafts 30 and 31 so that the latter must rotate with the sleeves although the shafts are capable of sliding movement through the sleeves.

On the sleeve 45 on the horizontal scraper shaft 30 are fixed or formed three similar chain sprocket wheels 47, 48 and 49 arranged at axially spaced intervals along the sleeve.

The sleeve 46 on the other scraper shaft 31 is provided with a single sprocket wheel 50 which is aligned with the rear sprocket 49 on the sleeve 45 on the scraper shaft 39 and an endless chain 51 passes over these two aligned sprocket wheels so that the two shafts 30 and 31 may not rotate independently but always turn in unison.

Between the said top scraper carriage guide rails 35, and at one end thereof, is provided a bracket 52 in Which a guide sprocket wheel 53 is mounted for free rotation about a horizontal axis perpendicular to the guide rails, this sprocket wheel being aligned with the central sprocket wheel 48 on the sleeve 45. A further driving, sprocket wheel 54, aligned with the front sprocket wheel 4-7 on the sleeve 45, is fixed upon the driving shaft 55 of a hydraulic torque motor 56 carried in a bracket 57 rigidly mounted on the outside of the superstructure 36, the motor 56 being located to the right-hand side of the said oblong frame 11 viewing machine 7 from the rear.

To the centre sprocket 48 on the sleeve 45 on the scraper shaft 30 is fixed one end of a roller chain 58 which passes partially round this sprocket (as will be clearly seen from FIGURE 11) in an anti-clockwise direction (as seen from the rear) and over the top of the same and then extends substantially centrally below the guide rails 35, over the freely rotatable guide sprocket 53 and then slightly diagonally over the top of the top scraper carriage and then around the driving sprocket 54- on the driving shaft 55 on the torque motor 56 after which the chain 58 again passes below the top scraper carriage and then in an anti-clockwise direction (seen from the rear) over and partially around the front sprocket 47 on the scraper shaft 30, this end of the chain being secured to this sprocket. Thus any rotation of the driving sprocket 54 tends to rotate the front and centre sprockets 47 and 43 on the scraper shaft 31 in the same direction and to rotatethe scraper 28 carried by said shaft in that direction.

As the scraper shaft 31 rotates the other scraper shaft 31 must rotate similarly because of the chain drive 51 between the rear sprocket 49 on the scraper shaft 30 and the aligned sprocket St? on the scraper shaft 31.

However provision is made whereby the scraper shafts 30 and 31 are only rotated at the opposite ends of the reciprocating movement of the scraper carriage 34 and then only through about 90. Thus the scraper shaft 31 is extended rearwardly beyond its rearmost journal 33 on the top scraper carriage and into a friction clutch assembly comprising a housing 59 secured to the rear of the carriage 34. On the rear end of this scraper shaft 31 is slidably keyed a sleeve 60 which carries at least one friction disc 61 adapted to engage a friction ring 62 coaxially fixed to the rear surface of the front end of the housing 59. About the rear end of the sleeve 60 is concentrically and slidably mounted a further sleeve bearing a further friction disc 63 and adapted to engage a friction ring 64 located between the discs 61 and 63. The disc 63 is prevented from rotating in the housing 59 by lugs 65 on the disc engaging in radial stops 66 Within the housing 59. The slidable friction disc 63 is urged by a spring 67 towards the front end of the housing 59. The adjustment of the frictional resistance to the rotation of the shaft 31 with respect to the housing 59 is effected by means of a cap 68 engaging the pressure spring 67 and adjustable with respect to the housing 59 by means of a screw and nut arrangement 69.

The frictional resistance between the friction discs 61 and 63 and the static friction surfaces is adjusted to such a value that the tension in the driving chain 58 connected to the front and centre sprockets 47 and 48 on the sleeve 45 of the scraper shaft 30, cannot rotate this scraper shaft until such time as the endwise movement of the top scraper carriage, under the action of the torque motor and the said driving chain, is arrested by engagement with stops on the guide rails 35, there being a pair of stops 70 near one end of the guide and a further pair of stops 71 at the other end of such rails. The said stops 70' and 71 may be adjustable on the guide rails 35, these stops being so located that they arrest the carriage 34 in such end positions that either the scraper shaft 30 or the scraper shaft 31 is positioned approximately respectively at the centre of curvature of the corresponding arcuate corner 25 or 24 of the sealing surfaces of the door being cleaned.

At the commencement of a cleaning operation the lefthand (seen from the rear of the machine) scraper blade 29 will be somewhat to the left of the vertical medial plane of the door with the scraper blade in a horizontal plane as shown in FIGURE 12. The right-hand scraper blade 28 will, at this stage, extend vertically from its shaft 30.

If the torque motor 56 is now energised so as to rotate the driving sprocket 54 in an anti-clockwise direction as seen in FIGURE 11, the carriage 35 will be moved to the right as indicated by the arrow in FIGURE 12 since the friction exercised by the friction clutch assembly in the housing 59 is such as to prevent at this stage the rotation of the scraper shafts 3t and 31. Thus as the carriage 34- travels to the right, the right-hand scraper 28 will scrape the adjoining horizontal sealing surfaces of the oven door.

When the scraper carriage reaches and engages the righthand stops 70 on the guide rails 35 these arrest its further movement to the right, and at this stage the pull in the driving chain 58 overcomes the friction exerted by the clutch assembly so that clutch slip occurs and the scraper shafts 3t) and 31 are caused to rotate about their own axes in a clockwise direction through about a right angle whilst the carriage remains stationary, the scraper 28 on the right-hand shaft 30 turning in a clockwise direction from a vertical position to a horizontal position or just beyond such position during which movement this scraper blade effects the scraping and cleaning in an outward and downward direction of the right-hand arcuate corner 23 of the sealing surfaces at the top corner of the door. Simultaneously with this movement of the right-hand scraper into a horizontal position, the left-hand scraper moves to a vertical position and at this stage this scraper has passed to the right of the said medial plane of the door, this final position being illustrated in full lines in FIGURE 11.

At this stage the rotation of the torque motor 56 is reversed so that the carriage 34 commences to move to the left with the right-hand scraper blade 28 in a horizontal position and the left-hand scraper blade 29 in a vertical position so that the latter blade scrapes the sealing surfaces from somewhat to the right of the centre thereof, this scraping continuing until the carriage is arrested at the left-hand end of its movement when the left-hand scraper will turn in a clockwise direction through 90 or rather more to scrape the left-hand arcuate upper corner 24 of the sealing surfaces of the door in an outward and downward direction whilst the right-hand scraper 28 turns from its horizontal position in an anti-clockwise direction to a vertical position ready for the return of the carriage to its starting position shown in FIGURE 12. Thus the deposits on the upper horizontal sealing surfaces 22 and the arcuate corners 24 and 25 of this upper part of the sealing surfaces are scraped away from approximately the centre of the door outwardly and downwardly, some of the deposits being pushed to the right and downwardly by the scraper 28 and the remainder of the deposits being pushed to the left and downwardly by the scraper 29.

The shaft 55 of the torque motor 56 rotates in each direction through about 270 but provision is prefer ably made for adjusting the degree of angular rotation of this shaft, the angular rotation of the blades 28 and 29 depending upon the angular movement of the torque motor shaft.

The scraping unit for cleaning the bottom part 23 and arcuate corners 26 and 27 of the sealing surfaces of the door is similar in construction and function to the top scraping unit but the arrangement is such that the scrapers are arranged to start their scraping at the top of the arcuate lower corners 26 and 27 of the door sealing surfaces and to propel the removed deposits inwardly to the centre of the door, the paths of movement of the scrapers overlapping one another as in the case of the scrapers of the top scraping unit of the machine.

Thus the bottom scraping unit (which is shown in FIGURES 8, 9, 10 13 and 14 in particular) comprises, like the upper scraping unit, a pair of scraper blades 72 and 73 respectively fixed in a radial position (preferably replaceably) to the front end of scraper shafts 74 and 75 so as to project forwardly therefrom along the diametrical plane of the shaft. The said two scraper shafts 74 and 75 are arranged in parallelism in the same horizontal plane and are spaced laterally from one another, being journalled at spaced positions along their lengths in bearings respectively marked 76, 76 and 77, 77 in the drawings, the said bearings are provided on a carriage 7 8, hereinafter referred to as the bottom scraper carriage, which is reciprocable along a pair of guide rails 79 fixed horizontally across the lower portion of the framework of the machine 7 and behind the said oblong frame at a level such that the scraper shafts 74 and 75 are, when in use, substantially opposite the horizontal bottom sealing surface 23 of the door.

The said guide rails are conveniently in the form of a pair of angle section members arranged in opposition each with one flange directed horizontally inwardly. The carriage 78 comprises a horizontal plate 80 having a pair of webs 81 depending therefrom between the guide rails 79, these webs each carrying, on the outsides thereof, two pairs of upper and lower rollers 32, these pairs of rollers being spaced longitudinally of the carriage and the upper rollers engaging the upper surfaces of the inwardly directed flange of the adjoining guide rail 79 and the lower rollers engaging the under surfaces of such flange, the carriage thus being located against up and down movement but free for horizontal endwise move ment along the guide rails.

Lateral movement of the carriage 78 with respect to the guide rails 79 is precluded by providing rollers 83 which rotate on vertical spindles located on the insides of the said dependent webs 81 of the carriage, the rollers passing through slots in the dependent webs and bearing upon the inner edges of the horizontal inwardly directed flanges of the adjoining guide rails.

To regulate the freedom of movement of the carriage 78 along the guide rails 79 and to hold the carriage against movement along the guide rails 79 in certain circumstances as hereinafter explained, there is provided a friction brake comprising an adjustable friction shoe 84 resiliently mounted (see FIGURES 9 and 13) on the carriage 78, this shoe bearing upon a friction strip or pad 85 secured to the upstanding flange of the rear guide rail 79 for the bottom scraper carriage 78.

The friction shoe 84 is carried at the front ends of a pair of horizontal rods 86 (FIGURE 9) slidable in horizontal externally screw threaded sleeves 87 mounted in a dependent arm of a bracket 88 fixed to the plate 80 of the carriage 78, the sleeves 87 being adjustable in the bracket 88 and securable in any of their adjusted positions by lock nuts 89, and a compression spring 90 being arranged between each of the front and sleeves 87 and the friction shoe 84 and around the corresponding shoe carrying rod 86.

The scraper shafts '74 and 75 are capable of limited endwise sliding movement in their bearings 76 and 77 and are urged forwardly respectively by helical springs 91 and 92 engaging at their front ends collars 93 and 94 fixed upon the shafts 74 and 75, said springs engaging at the rear ends against the front ends of sleeves 95 and 96 respectively keyed on to the shafts 74 and 75 so as to rotate with these shafts but to permit the latter the said limited axial movement through the sleeves.

The sleeve 95 on the right-hand scraper shaft 74 has three axially spaced similar sprocket wheels formed integrally thereon or rigidly secured thereto, these sprocket wheels being respectively marked 97, 98 and 99 in the drawings.

Similarly the sleeve 96 on the left-hand scraper shaft 75 has a single sprocket wheel 100 integrally formed or fixed thereon, this sprocket wheel being aligned with the rearmost sprocket wheel 99 on the sleeve 95 of the right-hand scraper shaft 74.

To the centre sprocket wheel 98 on the sleeve 95 is fixed one end of a roller chain 101 which passes partially around this sprocket in a downward and clockaosaeas wise direction (as seen from the rear as in FIGURE 13) and thence rectilinearly to the left of the carriage 78 and centrally over the guide rails 79 as will be seen from FIGURE which, of course, is also a view looking from the rear of the mechanism. The chain 181 then passes downwardly over a freely rotatable sprocket wheel 102 mounted in a bracket 10 3 between the left-hand ends of the guide rails 79 and from this sprocket the chain 161 extends approximately centrally between the two guide rails 79 and under the scraper carriage 78 to a driving sprocket wheel 104 located beyond the right-hand end of the guide rails and fixed upon the shaft 1115 of a reversible hydraulic torque motor 1% carried by a bracket 107 secured to the right-hand side of the frame-work of the machine 7 by which the said rectangular frame is carried. After passing upwardly over the driving sprocket 104 the chain 181 extends inwardly towards the bottom scraper carriage 78 and has its second end secured to the front sprocket 97 of the series of three sprockets on the sleeve 95 on the right-hand scraper shaft 74, the chain passing under and partially around this sprocket in a clockwise direction before being fixed thereto.

The rear sprocket 99 of the said series of three sprockets and the aligned sprocket 1150 on the sleeve 96 of the scraper shaft 75 carry an endless chain 108 that extends around both of the sprockets so that both scraper shafts must rotate in synchronism with one another at the same rotational speed.

As in the case of the top scraper unit, the scraper shafts 7d and 75 of the bottom scraper unit are limited to a rotational movement of 90 or slightly more. In the case of the bottom scraper unit positive stop means are provided for limiting the rotational movement in one direction of each of the shafts 74 and 75, these stop means comprising radial arm 189 and 110 respectively fixed to the rear ends of the shafts 74 and 75 and adapted for cooperation respectively with the opposite ends of the bracket 88 on the rear of the carriage 78.

As previously explained, it is preferred that one of the scraper blades 72, 73 of the bottom horizontal sealing surfac scraper unit should commence its action at the upper end of one of the arcuate lower corners 26, 27 of the sealing surfaces and move downwardly and then inwardly, after which the other scraper of the unit will scrape the opposite lower arcuate corner of the sealing surfaces and scrape downwardly and then inwardly.

Assuming that the bottom scraper carriage 78 is at the right-hand limit of its movement as seen from the rear, as shown in FIGURE 13 and that the right-hand scraper blade 72 is in a substantially horizontal position, on the torque motor 106 being operated in the appropriate direction, the scraper blade 72 will be rotated in a clockwise direction and will scrape the lower right-hand radiused corner 26 of the sealing surface with which it is registered and not until the scraper 72 has reached a substantially vertical dependent position and has been arrested from further rotation by the arm 10 9 engaging the bracket 88 will the carriage 78 commence to mov along its guide rails 79, the carriage having been so far restrained from longitudinal movement by the engagement of the friction shoe 84 with the friction pad 85 on the adjoining carriage guide rail 79. However, when the rotational movement of the righthand scraper shaft is arrested, the carriage 78 is compelled to move to the left under the pull of the chain 101, the right-hand scraper blade 72 thus being caused to travel along the lower horizontal sealing surface 23 of the door and cleaning the latter and continuing to do so to a position somewhat to the left of the vertical medial plane of the door.

At the commencement of the scraping operation just described the scraper blade 73 on the left-hand scraper shaft 75 occupies the dependent vertical position in which it was at the end of the previous left-to-right scraping stroke of the carriage. However, as the right-hand scraper 72 turns from its horizontal to its vertical position, the

12 left-hand scraper blade 73 moves from its vertical to a horizontal position in which it is directed to the left from its shaft 75.

Thus, when the scraper carriage 78 has moved fully to the left, the left-hand scraper blade 73 is approximately horizontally positioned ready for effecting a downward and inward scraping of the left-hand arcuate corner 27 of the sealing surfaces of the door so that, on the reversal of the torque motor 1116, this corner is first scraped downwardly and inwardly while the carriage 78 is stationary and then, on the left-hand scraper blade 73 reaching its vertical position, the carriage moves to the right so that the blade 73 continues its inward scraping movement and overlaps the path previously scraped by the right-hand scraper blade 72, the deposits removed from the sealing surfaces thus being drawn to the centre of the door and deposited in a trough or other collecting vessel (not shown) placed below the door. FIGURE 14 illustrates the last mentioned phase in the scraping operation.

Referring to FIG. 3, behind the oblong frame 11, and within the yokes 12, are arranged a pair of parallel laterally spaced guide rails 111 which extend vertically from the lower to the upper of the yokes and which are arranged symmetrically with respect to the frame 11 and in a plane parallel thereto, the rails 111 conveniently being secured to the side arms of the yokes 12 and being of right-angled form so that one flange of each rail projects inwardly at right angles to the corresponding sides of the yokes 12 as shown clearly in FIGURES 2 and 3.

On th se guide rails 111 is mounted a vertically reciprocable carriage 112. This carriage comprises a pair of vertical laterally spaced side plates 113 rigidly secured together by a horizontal cross beam 114.

Each of the said side plates 113 is furnished with two pairs of horizontally spaced guide rollers, an upper pair 115 and a lower pair 116, the rollers of these several pairs rotating on axes perpendicular to the side plates 113 and engaging between them the inwardly directed flanges of the guide rails 111 so that the carriage is free to reciprocate up and down these rails.

To locate the carriage 112 against lateral displacement elatively to the guide rails 111, the carriage is also furnished at each side thereof with a roller 117 rotatable on an axis parallel to the adjoining side plate 113 and bearing on a runner 118 extending vertically between the upper and lower yokes 12.

The carriage 112 is furnished with means for cleaning the vertically arranged or side sealing surfaces 21, 21 of the door and for this purpose it is necessary that the carriage 112 should be reciprocated up and down the guide rails 111. Whilst any suitable mechanism may be used to effect this reciprocation, such as screw and nut mechanism, it is preferred to employ the mechanism shown in the drawings (particularly in FIGURES 1, 2 and 3) which comprises a pair of endless chains 118 arranged in spaced parallel planes and each attached at a point 119 to the carriage 112 at one position in the length of the chain, the latter then passing from the carriage vertically upwardly and vertically downwardly and respectively over and under upper and lower pairs of freely rotating spaced sprocket wheels respectively marked 12% and 121 and mounted on the framework of the machine 7, the upper and lower portions of each chain then extending respectively downwardly and upwardly from the said pairs of sprocket wheel and respectively over freely rotating sprocket wheels 122 and 123 and around a driving sprocket 1'24 fixed upon the output shaft 125 of a reduction gear box 126, the input shaft 127 of which is driven by a reversible motor 128 which, in this case, is a reversible hydraulic motor.

In order automatically to retard the movement of the carriage 112 and to bring it to rest as it reaches the upper and lower ends respectively of its travel, appropriate trip units 129 and 1341 are respectively provided near the upper and lower ends of the guide rails 111, 

1. A METHOD OF CLEANING THE SELF-SEALING METAL SURFACES BETWEEN THE DOORS OF HORIZONTAL COKE OVENS AND THEIR COOPERATING DOOR FRAMES WHILE HOT FROM THE HEAT OF THE OVEN STRUCTURE, COMPRISING: HORIZONTALLY MOVING A CARRIAGE CONTAINING TWO SETS OF MECHANICALLY RECIPROCATED SCRAPERS WITH EXTRANEOUS HEATING MEANS THEREOF INDIVIDUALLY INTO POSITION WITH SELF-SEALING SURFACES AFORESAID BETWEEN INDIVIDUAL ONES OF DOORS AND THEIR FRAMES FOR CLEANING SELF-SEALING SURFACES AFORESAID, APPLYING EXTRANEOUS HEAT TO THE DEPOSITS OF PITCHY CONSTITUENTS OF THE GAS FROM THE OVENS ON THE AFORESAID SURFACES TO BE CLEANED, AND THEREUPON SCRAPING OFF THE SOFTENED DEPOSITS BY SAID MECHANICALLY RECIPROCATED SCRAPERS. 